This potato leek soup proves that a few humble ingredients can make something wonderful. Leeks cooked slowly in butter turn sweet and silky, Yukon Gold potatoes make the soup naturally creamy, and a little cream finishes it off. It is the kind of soup French home cooks have made for generations.
Cleaning leeks properly
Leeks grow in sandy soil, and grit hides between the layers. Slice them first, then put the slices in a big bowl of cold water and swish them around. The sand sinks to the bottom. Lift the leeks out with your hands or a slotted spoon instead of pouring them into a colander.
Cook the leeks low and slow
Ten minutes over medium-low heat lets the leeks soften and release their sweetness without browning. Browned leeks taste bitter and turn the soup gray. A pinch of salt helps them release their moisture.
The best potatoes for soup
Yukon Golds are the top choice: buttery, creamy and smooth when blended. Russets work but can turn gluey if blended too long. Red potatoes are better for a chunky soup because they hold their shape.
Don't overblend
Potato starch becomes sticky when overworked. Blend just until smooth, and use an immersion blender or a countertop blender on low speed. Never use a food processor for potato soup.
Vichyssoise: the cold version
Chill the blended soup, thin it with a little more cream and serve it cold with chives. This French classic, called vichyssoise, is a lovely starter on a hot day.
Add-ins and toppings
Crispy bacon, shredded cheddar, a spoon of sour cream, garlic croutons or a drizzle of truffle oil all work. For a heartier soup, stir in cooked ham or smoked sausage after blending.
Make it vegan
Use olive oil or vegan butter, vegetable broth and unsweetened oat milk or cashew cream. The potatoes already give plenty of body, so the soup stays creamy.
Serving ideas
A loaf of crusty bread and a green salad make it a full meal. If you love velvety soups, try our cream of mushroom soup or the cheesy broccoli cheddar soup.
Storing and freezing
Leftovers keep for 4 days in the fridge. Potato soups can turn slightly grainy when frozen; if you freeze it, leave out the cream, and blend again briefly after thawing.
A soup with a long history
Potato and leek soup is one of the oldest home recipes in France, where it is called potage Parmentier, after the 18th-century scientist who convinced the French to eat potatoes. In Wales, leeks are a national symbol, and leek soups are served on Saint David's Day.
Make it with fewer dishes
If you do not own an immersion blender, use a potato masher right in the pot. The soup will be rustic and chunky, which many people prefer. Stir in the cream after mashing to bring it together.
Leftover ideas
Thick leftover soup makes a great sauce for baked fish or chicken. You can also pour it over sliced potatoes with grated cheese and bake it into a quick gratin.
Is it a good budget meal?
Very much so. Leeks, potatoes, butter and broth are inexpensive all year, and one pot feeds six people for the price of a single café lunch.
Frequently asked questions
Can I use the dark green parts of the leeks?
They are tough and bitter in the soup, but they are perfect for making homemade broth.
Why is my potato soup gluey?
The potatoes were blended too long or too fast. Use waxy or Yukon Gold potatoes and blend only until smooth.
Can I make it without cream?
Yes. The potatoes make it creamy on their own; finish with a knob of butter instead.
